Method for the preparation of polyamide-imides
CA 2074919 A1 · Owner: Perry, Robert J. · Inventors: Perry, Robert J.; Turner, S. Richard; Blevins, Richard W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preparing a polymer including the step of reacting carbon monoxide and a reactant pair having respective general formulas , and, or a reactant pair having respective general formulas , and, or a reactant having the general formula X is a nonortho halide selected from the group consisting of Br and I. n is an integer from 0 to 4 d, is an integer from 0 to 1 and e is an integer from 0 to 3. If d is 0, then e is 0. R1 is selected from the group consisting of alkyl, arylalkyl, aryl heteroaryl, and cycloalkyl. R2 is selected from the group consisting of -O-, -S-, , , , , , , -C?C- , , , -(CF2)m, and , wherein each R5 is independently selected from the group consisting of alkyl and …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed July 29, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 29, 2014.
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Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.